I have an Indian passport issued in

I have an Indian passport issued in Delhi which expires on 27 Dece 2015 and after the Non-B done by the Immigration Bureau,Bangkok, now only just one side page left. My Noon-B is ffor 3 months expires on 22 Sept.
I have been working in Phayao,Northern Thailand since 2010 as a teacher but my work permit got expired on March,2014 as I was in New Delhi, India.. Then I couldn't process my documents , so I was back to Thailand on Tourist visa,then non-b was processed.
So what should I do? Should I apply for a new Passport? If I apply for a new passport,then the expiry of the passport will also be extended? I have a regular passport and so I should apply for how many pages? Since I won't be having the work permit now, will the contract from the school and a letter from the school will help as the supporting